WO 2009/076959 A1 discloses a dispensing device for dispensing doses of liquid medium. The dispensing device comprises a first chamber and a second chamber divided from each other by an intermediate wall arranged in an interior part of the dispensing device. An inlet passage establishes a fluid connection between the first chamber and an interior part of a container containing the liquid product, and an outlet passage allows liquid product to be dispensed from the second chamber. An intermediate passage is defined at a position of an edge of the intermediate wall, thereby allowing a dose of liquid product to pass from the first chamber to the second chamber. The intermediate wall comprises a portion which is inclined or curved in a direction towards the first chamber. Thereby the first chamber defines a cavity or bowl-shaped region which traps liquid product when the dispensing device is oriented in a certain direction during a dispensing movement. This prevents liquid product from passing directly through the dispensing device.
One disadvantage of the dispensing device of WO 2009/076959 is that there is a risk that a vacuum is formed in the container during dispensing, and that such vacuum can result in errors in the doses being dispensed by means of the dispensing device.